Orthogonal frequency-division multiplexing (OFDM) can refer to a method of encoding digital data on multiple carrier frequencies. In OFDM, sub-carrier frequencies can be chosen so that the sub-carriers are orthogonal to each other. In such cases, cross-talk between the sub-channels may be reduced and inter-carrier guard bands may not be required. OFDM can be used for digital communication, used in applications such as digital television and audio broadcasting, DSL Internet access, wireless networks, powerline networks, and mobile communications.
Further, an OFDM carrier signal can be the sum of one or more orthogonal sub-carriers and/or tones. Further, baseband data on each sub-carrier can be independently modulated, for example, using quadrature amplitude modulation (QAM) or phase-shift keying (PSK) and/or the like. This composite baseband signal can be used to modulate a main RF carrier.